If you aren’t measuring energy con- sumption, you aren’t managing it. Most FMs don’t need to learn that fact. But how exactly to measure it and what metrics to use? The ongoing tactic and long-term strategy must involve performance
tracking. The rub is that building
automation systems (BAS) can generate
such deep and fast-moving rivers of
data that it is hard for operators to pan
the gold nuggets that lead to profitable
outcomes. It can also be so time
consuming that few can stick to it.

The solution is to track key metrics, not
data points. A metric merges data from
multiple points into a measurement that
provides ready-to-act-on insight. Older
automation systems may not offer slick
dashboards, but operators can still create
and display data to glean money-saving
information.

Two Methods for Tracking Metrics

In its Building Performance Tracking
Handbook: Continuous Improvement for
Every Building, the California Energy
Commission (CEC) supplies an example of
the difference between data and metrics.

While collecting data on indoor
zone temperatures provides useful
information, over time the size of the data
becomes immense. Instead, an operator
can create a metric that tracks the percent
of time when zones maintain their
temperature setpoints. At a glance, this
metric displays the key information.

Ideally each metric should have atarget associated with it. If questions andanomalies arise, operators can drill downinto the data as necessary.

A BAS can be used to track metrics in
two complementary ways:

n Charts or plots that display patterns
over days, weeks, months and years

n Values (averages, minimum/maximums
and percentages)

With such patterns displayed, operatorscan get an instinctive feeling for howchanging occupancy, weather and othervariables affect HVAC efficiency.

The most common energy metrics are
cost or energy units per square foot per
year. Most do not have hard values or
limits, which is to say that operators learn
over time how their buildings perform.